/*
For any positive integer k, a finite sequence ai of fractions xi/yi is defined by:
a1 = 1/k and
ai = (xi-1+1)/(yi-1-1) reduced to lowest terms for i&gt;1.
When ai reaches some integer n, the sequence stops. (That is, when yi=1.)
Define f(k) = n. 
For example, for k = 20:



1/20 → 2/19 → 3/18 = 1/6 → 2/5 → 3/4 → 4/3 → 5/2 → 6/1 = 6



So f(20) = 6.



Also f(1) = 1, f(2) = 2, f(3) = 1 and Σf(k3) = 118937 for 1 ≤ k ≤ 100.



Find Σf(k3) for 1 ≤ k ≤ 2×106.

Anser:
Time:
*/
package main

import (
	"fmt"
	"time"
)

func main() {
	tstart := time.Now()



	tend := time.Now()
	fmt.Println(tend.Sub(tstart))
}